Noun

1. The process of aggregating or coalescing into a mass.
2. A solid, hard mass formed by a process of aggregation or coalescence.
3. A rounded mass of a mineral, sometimes found in sedimentary rock or on the ocean floor.
   • 1844, Charles Darwin, Geological Observations on South America, ch. 5,

     Of the three beds, the central one is the most compact, and more like ordinary sandstone: it includes numerous flattened spherical concretions.

4. The action of making something concrete or the result of such an action.
   • 1860, Nathaniel Hawthorne, The Marble Faun, ch. 14,

     "My new statue!" said Kenyon. . . . "It is the concretion of a good deal of thought, emotion, and toil of brain and hand."

Usage notes

• Concretion and concretization are rough synonyms but are usually not used interchangeably. Concretion is more commonly used to refer to a physical object or to the physical process which creates it. Concretization is more commonly used to refer to a particular embodiment of a general concept or to the process which creates it.